Rocket Report: Key Dragon test on tap, big year for rocket debuts

wrote Maezawa on a website for applicants. "I want to find a 'life partner.' With that future partner of mine, I want to shout our love and world peace from outer space."

Was puzzled at why a guy with money to buy a Starship from SpaceX would have trouble getting a date... Not anymore.

One does imagine that there should still be several thousand willing wannabe stars with the urge to hitch themselves to his Starship - if the citizens of L.A. are any indicator - despite evidence this might not be a good idea (eg. Weinstein, et-al).

Angella King ( @PicklePunchD )"Elon? on what criteria do you think the 100k people will be chosen? Will there be a lottery once all the essential positions are filled or will they all be hired based on skill sets?

Wondering at what number we are likely to see families go to Mars."

Elon Musk:"Needs to be such that anyone can go if they want, with loans available for those who don’t have money"

K10 ( @Kristennetten )"Work off the loans?"

Elon Musk:"Yes. There will be a lot of jobs on Mars!"

What does Elon think the Martian colony is going to produce to pay off those loans and buy everything else the settlers will need just to survive? Extraterrestrial colonization will not be economically viable until zero G manufacturing is large enough to make off world mining profitable, and then the moon and asteroids will be more attractive. Insert joke about the evils of colonialism here.

What does Elon think the Martian colony is going to produce to pay off those loans and buy everything else the settlers will need just to survive? Extraterrestrial colonization will not be economically viable until zero G manufacturing is large enough to make off world mining profitable, and then the moon and asteroids will be more attractive. Insert joke about the evils of colonialism here.

While I admire the way Elon and SpaceX are pursuing extraodinary dreams, I don't understand the project of Mars colonisation at this point.

Of course, a scientific outpost would be useful for all sorts of projects, for example looking for primitive lifeforms or radioastronomy away from earth noise, but colonisation? We don't even know if it is safe for humans to live long term in reduced grav.

A great project for the next thousand years would be to turn Mars or Venus [back] into a living planet, creating a atmosphere (picking gas from some other place in the solar system, for example) and allowing all sorts of lifeforms to strive in that environment.

Angella King ( @PicklePunchD )"Elon? on what criteria do you think the 100k people will be chosen? Will there be a lottery once all the essential positions are filled or will they all be hired based on skill sets?

Wondering at what number we are likely to see families go to Mars."

Elon Musk:"Needs to be such that anyone can go if they want, with loans available for those who don’t have money"

K10 ( @Kristennetten )"Work off the loans?"

Elon Musk:"Yes. There will be a lot of jobs on Mars!"

What does Elon think the Martian colony is going to produce to pay off those loans and buy everything else the settlers will need just to survive? Extraterrestrial colonization will not be economically viable until zero G manufacturing is large enough to make off world mining profitable, and then the moon and asteroids will be more attractive. Insert joke about the evils of colonialism here.

you wouldnt go to another planet for Zero g manufacturing you can go Earth sourced staying in LEO, far more economical than going to Luna or astroids as the spacecraft that are needed to bring down finished product to Earth can bring up raw materials, initially I suspect it will be status products and marketing. Other ventures would make up the difference, until it grows enough to be mostly self sufficient

I remember one statement that the provisions for connecting modules are costly - weight, complication, assembly difficulty, maintenance, failure points, etc. It's much easier to build a large station if the modules don't have to be so small.

This is a reason to build a large rocket.

It's not a reason to build an expendable rocket. Or to use Shuttle-derived tech which has proven to be obscenely expensive even when it was reused.

[....] A great project for the next thousand years would be to turn Mars or Venus [back] into a living planet[....]

When it comes to living off-world, terra forming is not efficient use of resources and time. You could achieve significantly more with in-space habitats.

I did some math.

If you consume the raw mass of Mars as a source for space habitats you would have almost 18x the total surface area of Earth!!! (~59x of Mars) or the equivalent (surface area) of planet with diameter of 52'809km. (a bit larger than Uranus)

It will come in the form of 72'626 artificial space islands.Each habitat will have diameter of 100km and length of 500km.The thickness (from ALL sides) will be 10km (ten kilometers) with average density of 5000kg/m3The base surface area of each habitat would be 120'637km2 The outer structure I'm estimating (wild guess) to represent 80% of the total mass of the habitat. (the other mass comes as ~1.77 billion gigatons)

You could form a single ring with diameter of ~0.707AU (to have 2x the solar intensity than Earth) In that case they (the habitats) would be 9'151km apart. (~91habitats length)

To provide 1g (for the inner surface), the rotation rate would be ~0.12 rpm or period of 8min:22sec.

If you consume Ceres's mass you could make 106 such habitats with total base surface area of 12.8 million km2 - That represent area that is 30% larger than Canada's or 92% of the arable land of Earth.

Though if you are willing to lower the outer walls thickness to 485m and the average density to 3000kg/m3 then with one Ceres mass we could get as much surface as the whole Earth. (across 3'300 habitats X 155'254 km2 each) Or ~3.52x Mars's surface area.- - - - - - - - - - - - -

We kinda assume that when going interstellar we need to settle on planets capable of supporting life.

False.All we need is just the raw mass to consume. We don't even need planets. We just need the stars. Though star-lifting is kinda more demanding.

Each of the habitats would have it's own gravity, it's own climate, own government and society.

Being stuck on some planet (whatever the planet is) means we are simply too primitive as far as technology goes. Waiting for nature to care for us. To provide the gravity, to provide the climate. Really?

We need to step up and become more independent entities. Make our own planets. Up to spec. (later on, we will make our own stars and even galaxies but this is too far along the evolution tree)

I don't think I'm going out on a limb to say that Russia is unlikely to get their superbooster, Oryel capsule and moonbase. When your buildings are crumbling, garbage is piling up, and your best and brightest minds end up going into oil and gas engineering, these plans are worse than pie in the sky. They are lies told to the Russian citizens to try and convince them that Russia is a space superpower, and told to the world to tell them that they are still great and glorious, and that we should fear them. That's why they continue to work on superweapons that they can't afford to mass produce, and samples that are unlikely to work when needed.

As for the idea that the superfast merrygoround will be put on Navy ships as some sort of weapon: not ever going to happen. The Navy is making a lot of progress on lasers and rail guns, which are more compact than spindizzy's gizmo. Lasers are going to be used for anti-missile defense, and smaller lasers are being tested as dazzlers to use against small boats such as the Iranians used. Railguns will be employed in anti-ship and land bombardment roles.

I agree. National prestige has always been an important motivating factor in space flight, but Russia, from very early on in the Soviet era, has been very good at Potemkin Village productions that make for very good headlines as long as you don't look too closely at the reality. Their space program has often followed this example. Many of their "firsts" (first woman in space, first two craft in orbit simultaneously, first multi man crew, first EVA, etc.) were little more than publicity stunts that did not really help them solve the problems of living and working in space. In recent years, being the only country with routine ability to put people in orbit and providing America with access to the ISS has considerably enhanced their prestige. Good for them, and damn our politicians for putting us in that situation, but that is coming to an end. When Crew Dragon, Starliner, Orion, Starship, and maybe even Dreamchaser and New Glenn are all ferrying people in to space for various purposes, tending a variety of space stations built from Bigelow modules, flying to the moon and back, and preparing to go to Mars, the prestige offered by Soyuz will be minimal, perhaps even negative, and they do not have the resources to match any of that.

[....] A great project for the next thousand years would be to turn Mars or Venus [back] into a living planet[....]

When it comes to living off-world, terra forming is not efficient use of resources and time. You could achieve significantly more with in-space habitats.

I did some math.

If you consume the raw mass of Mars as a source for space habitats you would have almost 18x the total surface area of Earth!!! (~59x of Mars) or the equivalent (surface area) of planet with diameter of 52'809km. (a bit larger than Uranus)

It will come in the form of 72'626 artificial space islands.Each habitat will have diameter of 100km and length of 500km.The thickness (from ALL sides) will be 10km (ten kilometers) with average density of 5000kg/m3The base surface area of each habitat would be 120'637km2 The outer structure I'm estimating (wild guess) to represent 80% of the total mass of the habitat. (the other mass comes as ~1.77 billion gigatons)

You could form a single ring with diameter of ~0.707AU (to have 2x the solar intensity than Earth) In that case they (the habitats) would be 9'151km apart. (~91habitats length)

To provide 1g (for the inner surface), the rotation rate would be ~0.12 rpm or period of 8min:22sec.

If you consume Ceres's mass you could make 106 such habitats with total base surface area of 12.8 million km2 - That represent area that is 30% larger than Canada's or 92% of the arable land of Earth.

Though if you are willing to lower the outer walls thickness to 485m and the average density to 3000kg/m3 then with one Ceres mass we could get as much surface as the whole Earth. (across 3'300 habitats X 155'254 km2 each) Or ~3.52x Mars's surface area.- - - - - - - - - - - - -

We kinda assume that when going interstellar we need to settle on planets capable of supporting life.

False.All we need is just the raw mass to consume. We don't even need planets. We just need the stars. Though star-lifting is kinda more demanding.

Each of the habitats would have it's own gravity, it's own climate, own government and society.

Being stuck on some planet (whatever the planet is) means we are simply too primitive as far as technology goes. Waiting for nature to care for us. To provide the gravity, to provide the climate. Really?

We need to step up and become more independent entities. Make our own planets. Up to spec. (later on, we will make our own stars and even galaxies but this is too far along the evolution tree)

the natural gravity and existing but thin atmosphere on a planet like Mars is useful for logistics but even then its more efficient to have habs then when we do eventually decide to repurpose it as K2 source material everything is already sealed up making it much easier to manage than an open air habitable planet

I remember one statement that the provisions for connecting modules are costly - weight, complication, assembly difficulty, maintenance, failure points, etc. It's much easier to build a large station if the modules don't have to be so small.

This is a reason to build a large rocket.

It's not a reason to build an expendable rocket. Or to use Shuttle-derived tech which has proven to be obscenely expensive even when it was reused.

plus if a significant portion of the modules are capable of free flight, you could have "ship of Theseus" continual useful life,

Ford isn't quite as bad as the Zumwalt. A recent article I read said they started building it before the design was even completed! If that's not a recipe for disaster, the Russian and French navies would beg to disagree.

Ford just tried to put too much new tech together at the same time. All of the tech will be great for the next 50 years, but it seems they didn't have a sufficient handle on it from testing on land first.

If the parts they built before design was finished were already locked in, that isn't too horrible, the EM cat was basically a required feature otherwise not only would it not really have better capacity than Nimitz but it wouldn't be able to launch smaller aircraft such as drones because the steam cat lacks the the ability to drop its force that much

The build before design completion was an issue with Zumwalt, not Ford, and certainly has contributed to its issues, as well as a changing mission profile. It was originally envisioned as a shore bombardment platform to replace the battleships, hence the long range gun that was supposed to be able to lob shells 110 miles. In the end, they never got a range better than 70 miles, and the shells cost $800K apiece, not much different than a cruise missile. So now, they are re-purposing it as an anti-ship platform. They have no idea what to do with the guns, and it carries fewer VLS cells than the much smaller Arleigh Burkes.

My understanding is that further orders of the class have been cancelled altogether in favor of a new order of Arleigh Burkes.

What does Elon think the Martian colony is going to produce to pay off those loans and buy everything else the settlers will need just to survive? Extraterrestrial colonization will not be economically viable until zero G manufacturing is large enough to make off world mining profitable, and then the moon and asteroids will be more attractive. Insert joke about the evils of colonialism here.

Lots of industry analysts expect space to be a trillion dollar business in the next few decades. It is currently $360 billion:

That's why people like Google and Fidelity Investments have put money into SpaceX.

Mars is the sexy goal that attracts good engineers to work at SpaceX. But in reality, a Starship capable of reaching Mars will open up the entire inner solar system to development. The tourist trip they have sold to go around the Moon demonstrates they can reach the Moon, and there is no reason they can't also reach the Asteroid Belt.

Our solar system is full of raw materials and energy. SpaceX has talked about their plans to mine Mars' atmosphere and ice to make propellants. But there is no reason to *only* mine for propellants, and no reason to *only* do it on Mars. The solar flux near Earth is 4-10 times higher than the solar energy available in places on Earth. To the extent solar energy works down here, it will work much better up there. You can use that energy to turn raw materials into useful products that people will pay for.

Sure, set up a mining colony on Mars. Its history and geology have produced concentrated ores of various kinds, and we will probably find more once we start serious prospecting. But do that everywhere else, too.

As far as off-planet manufacturing, the laws of nature are the same everywhere. Any manufacturing process that works on Earth will work up there, too. If it requires air and gravity, we can supply those artificially. Some processes work *better* with zero-g or vacuum, and we have all of those we could ever want. The mass and energy return ratios for space manufacturing look to be very high. So that means once we have a "seed factory" set up, it should be able to grow rapidly.

As far as colonialism, I think the right model will be co-ops, the way my electric company is a member-owned cooperative. There are certain basic needs for a space colony (air, water, power, etc.) that you don't want some corporation making a profit off of. Then you get situations where if you haven't paid your bill, they cut off your air. A colony membership would then supply at least the basics to live. If you wanted more, you would have to pay extra.

Could we have such legislation (internationally recognized) that every company joining the space economy is required to provide certain output toward the collective (air, water, compute, base load power figure) without expecting payment. Like a tax if you want. Everything above the minimum output, they can sell and profit.

It's like sharing the common infrastructure. All parties contribute to maintain and expand it.

[....] A great project for the next thousand years would be to turn Mars or Venus [back] into a living planet[....]

When it comes to living off-world, terra forming is not efficient use of resources and time. You could achieve significantly more with in-space habitats.

[...]

There are two aspects.For humans, making giant rotating space stations, interplanetary spacecrafts and asteroid mining is probably better than trying to colonize Mars. At least as long as "living on Mars" means inside an airtight bunker. Because an artificial environment can be adjusted to imitate Earth.

But spreading life to other planets for millions of years and let new life forms emerge from different conditions (lower gravity would allow kilometer high trees?) is, for me, a more exciting goal.

I'm a bit fed-up with the "humans as a multi planerary species" meme. Because humans life depends on thousands of other Earth life forms, so it is not just about saving humans from the catastrophes they are triggering, it is about putting Earth DNA on another planet (if the planet is lifeless). Because if some humans ever live and procreate on Mars, it is very likely that after a few generations they won't be able to settle on high gravity Earth.

They want to install polluting mining on Mars because Earth has become a landfill and there is no exploitable raw resource anymore. I'd prefer Mars booming with life.

Launch Day = 80% 'Go'. Percentage does not include upper-level winds, which are poor.Backup Day = 80% 'Go'. Percentage does not include upper-level winds, which are poor (a little worse even than launch day).

Because humans life depends on thousands of other Earth life forms, so it is not just about saving humans from the catastrophes they are triggering, it is about putting Earth ADN on another planet (if the planet is lifeless).

Because if some humans ever live and procreate on Mars, it is very likely that after a few generations they won't be able to settle on high gravity Earth.

Evolution doesn't work that way. Natural selection doesn't just target a beneficial trait (reduced energy/nutrient consumption from reduced bone/muscle mass). There has to be a selective force, and "eating less" generally isn't something people notice when selecting mates. There would either need to be some intentional breeding program, or some kind of social bias towards more slender individuals. Even then, you're looking at tens of generations before noticeable change, not just a few.

However, what you describe would happen even among first generation immigrants. We're seeing it to a limited degree even just among long duration astronauts. It's likely immigrants would need to maintain some kind of regular gravitational therapy if they want to return to Earth (just as astronauts do). It's possible they would need to do it for purposes of general health.

Because humans life depends on thousands of other Earth life forms, so it is not just about saving humans from the catastrophes they are triggering, it is about putting Earth ADN on another planet (if the planet is lifeless).

Because if some humans ever live and procreate on Mars, it is very likely that after a few generations they won't be able to settle on high gravity Earth.

Evolution doesn't work that way. Natural selection doesn't just target a beneficial trait (reduced energy/nutrient consumption from reduced bone/muscle mass). There has to be a selective force, and "eating less" generally isn't something people notice when selecting mates. There would either need to be some intentional breeding program, or some kind of social bias towards more slender individuals. Even then, you're looking at tens of generations before noticeable change, not just a few.

However, what you describe would happen even among first generation immigrants. We're seeing it to a limited degree even just among long duration astronauts. It's likely immigrants would need to maintain some kind of regular gravitational therapy if they want to return to Earth (just as astronauts do). It's possible they would need to do it for purposes of general health.

Sorry. DNA.

You are right. "Fast" natural selection occurs if the survival rate is low, selective breeding will be applied to cattle, while humans will try hard to avoid to adapt (as we have always done, for example whites wearing more clothes to compensate from too much solar exposition in tropical area,...). An interesting "experiment"...

Angella King ( @PicklePunchD )"Elon? on what criteria do you think the 100k people will be chosen? Will there be a lottery once all the essential positions are filled or will they all be hired based on skill sets?

Wondering at what number we are likely to see families go to Mars."

Elon Musk:"Needs to be such that anyone can go if they want, with loans available for those who don’t have money"

K10 ( @Kristennetten )"Work off the loans?"

Elon Musk:"Yes. There will be a lot of jobs on Mars!"

What does Elon think the Martian colony is going to produce to pay off those loans and buy everything else the settlers will need just to survive? Extraterrestrial colonization will not be economically viable until zero G manufacturing is large enough to make off world mining profitable, and then the moon and asteroids will be more attractive. Insert joke about the evils of colonialism here.

Presumably they'll all get a share of the residuals from "The Real Housewives of Mars".

[....] A great project for the next thousand years would be to turn Mars or Venus [back] into a living planet[....]

When it comes to living off-world, terra forming is not efficient use of resources and time. You could achieve significantly more with in-space habitats.

I did some math.

If you consume the raw mass of Mars as a source for space habitats you would have almost 18x the total surface area of Earth!!! (~59x of Mars) or the equivalent (surface area) of planet with diameter of 52'809km. (a bit larger than Uranus)

It will come in the form of 72'626 artificial space islands.Each habitat will have diameter of 100km and length of 500km.The thickness (from ALL sides) will be 10km (ten kilometers) with average density of 5000kg/m3The base surface area of each habitat would be 120'637km2 The outer structure I'm estimating (wild guess) to represent 80% of the total mass of the habitat. (the other mass comes as ~1.77 billion gigatons)

You could form a single ring with diameter of ~0.707AU (to have 2x the solar intensity than Earth) In that case they (the habitats) would be 9'151km apart. (~91habitats length)

To provide 1g (for the inner surface), the rotation rate would be ~0.12 rpm or period of 8min:22sec.

If you consume Ceres's mass you could make 106 such habitats with total base surface area of 12.8 million km2 - That represent area that is 30% larger than Canada's or 92% of the arable land of Earth.

Though if you are willing to lower the outer walls thickness to 485m and the average density to 3000kg/m3 then with one Ceres mass we could get as much surface as the whole Earth. (across 3'300 habitats X 155'254 km2 each) Or ~3.52x Mars's surface area.- - - - - - - - - - - - -

We kinda assume that when going interstellar we need to settle on planets capable of supporting life.

False.All we need is just the raw mass to consume. We don't even need planets. We just need the stars. Though star-lifting is kinda more demanding.

Each of the habitats would have it's own gravity, it's own climate, own government and society.

Being stuck on some planet (whatever the planet is) means we are simply too primitive as far as technology goes. Waiting for nature to care for us. To provide the gravity, to provide the climate. Really?

We need to step up and become more independent entities. Make our own planets. Up to spec. (later on, we will make our own stars and even galaxies but this is too far along the evolution tree)

I assume that by 'own gravity' your talking about artificial gravity through centrifugal force, since thus far we don't even have a theory about how to make true artificial gravity.

The welders and machinists down in Boca Chica are remarkably restrained. All the graffiti I typically see on and around construction sites typically involves dicks, or nazis, or both. Maybe I just go to the wrong construction sites...

The welders and machinists down in Boca Chica are remarkably restrained. All the graffiti I typically see on and around construction sites typically involves dicks, or nazis, or both. Maybe I just go to the wrong construction sites...

The welders and machinists down in Boca Chica are remarkably restrained. All the graffiti I typically see on and around construction sites typically involves dicks, or nazis, or both. Maybe I just go to the wrong construction sites...

Most constructions sites don't have continuous zoomed in scrutiny by thousands of people on the internet.

Could we have such legislation (internationally recognized) that every company joining the space economy is required to provide certain output toward the collective (air, water, compute, base load power figure) without expecting payment. Like a tax if you want. Everything above the minimum output, they can sell and profit.

Right now, the Outer Space Treaty, to which every country going to space belongs, makes space hardware and astronauts the responsibility of the nation they come from. National laws still apply. So the various parts of the Space Station are under the jurisdiction of the nations who supplied them, and the crew are still citizens of their home countries. On Election Day, the US astronauts could vote from orbit.

A "company town" space habitat that treated their workers like slaves could not get away with it unless their home country allowed it. So a Chinese Moon base, maybe, but not an American one.

Launch Day = 80% 'Go'. Percentage does not include upper-level winds, which are poor.Backup Day = 80% 'Go'. Percentage does not include upper-level winds, which are poor (a little worse even than launch day).

L-2 weather forecast:

Launch Day = 80% 'Go'. Percentage does not include upper-level winds, which are poor.Backup Day = 70% 'Go'. Percentage does not include upper-level winds, which are poor (a little better than the L-3 forecast; now the same as launch day).

The welders and machinists down in Boca Chica are remarkably restrained. All the graffiti I typically see on and around construction sites typically involves dicks, or nazis, or both. Maybe I just go to the wrong construction sites...

Most constructions sites don't have continuous zoomed in scrutiny by thousands of people on the internet.

"There's cameras on us 24/7. If I see one swasticock, you're all fired."

Back to SpinLaunch after the drama from SpaceX this weekend. I had a good conversation with an engineer there. Yes, there's a lot of velocity lost due to aero drag, etc. but that's been accounted for. If you take middle-of-the-road numbers for unknowns, they feel they can get 100 kg to orbit - though they're looking to scale even larger. Unlike other launch companies this engineer had worked for, no impossible mass fractions or record-breaking ISP numbers are involved. He hinted it's not just a single kick motor from launch but there might be two full stages (he wasn't clear). He suggested you just think of it like a "normal" launch where your pad velocity is 3 km/s. He felt there were no showstopper technologies left. Everything they need to do they've done, they've just got to scale it bigger. And so far all the scaling has followed the rules for what they expected. Yes, there's a lot of (reusable) infrastructure required to launch their first payload but much of the energy is being supplied by recoverable electricity. Obviously the g loading limits the types of payloads, but that's a market question and not a physics limitation.

Back to SpinLaunch after the drama from SpaceX this weekend. I had a good conversation with an engineer there. Yes, there's a lot of velocity lost due to aero drag, etc. but that's been accounted for. If you take middle-of-the-road numbers for unknowns, they feel they can get 100 kg to orbit - though they're looking to scale even larger. Unlike other launch companies this engineer had worked for, no impossible mass fractions or record-breaking ISP numbers are involved. He hinted it's not just a single kick motor from launch but there might be two full stages (he wasn't clear). He suggested you just think of it like a "normal" launch where your pad velocity is 3 km/s. He felt there were no showstopper technologies left. Everything they need to do they've done, they've just got to scale it bigger. And so far all the scaling has followed the rules for what they expected. Yes, there's a lot of (reusable) infrastructure required to launch their first payload but much of the energy is being supplied by recoverable electricity. Obviously the g loading limits the types of payloads, but that's a market question and not a physics limitation.

The G-loading limits the types of rockets as well. They're going to be solid, and you're not going to be recovering them. It would seem their business plan fails as soon as Rocket Labs snags one of their boosters. Electron has a staging energy of around 2.5km/s, but they have a far more efficient upper stage, don't have to deal with thermals, don't have to deal with drag, don't have to perform a pull-up maneuver. I don't see them making orbit before the Great Smallsat LV Culling.

Back to SpinLaunch after the drama from SpaceX this weekend. I had a good conversation with an engineer there. Yes, there's a lot of velocity lost due to aero drag, etc. but that's been accounted for. If you take middle-of-the-road numbers for unknowns, they feel they can get 100 kg to orbit - though they're looking to scale even larger. Unlike other launch companies this engineer had worked for, no impossible mass fractions or record-breaking ISP numbers are involved. He hinted it's not just a single kick motor from launch but there might be two full stages (he wasn't clear). He suggested you just think of it like a "normal" launch where your pad velocity is 3 km/s. He felt there were no showstopper technologies left. Everything they need to do they've done, they've just got to scale it bigger. And so far all the scaling has followed the rules for what they expected. Yes, there's a lot of (reusable) infrastructure required to launch their first payload but much of the energy is being supplied by recoverable electricity. Obviously the g loading limits the types of payloads, but that's a market question and not a physics limitation.

The G-loading limits the types of rockets as well. They're going to be solid, and you're not going to be recovering them. It would seem their business plan fails as soon as Rocket Labs snags one of their boosters. Electron has a staging energy of around 2.5km/s, but they have a far more efficient upper stage, don't have to deal with thermals, don't have to deal with drag, don't have to perform a pull-up maneuver. I don't see them making orbit before the Great Smallsat LV Culling.

Solids or blow-down liquids. I agree. It was confirmed to me there's no turbomachinery - but that was sort of obvious. Electron putting them out of business is another market action but there doesn't appear to be anything limiting the physics - which I find amazing. The idea sounds incredibly crazy when you first hear it.

The engineer I was speaking to also mentioned an "on-orbit" version - perhaps as a slip. That is interesting as well.

The engineer I was speaking to also mentioned an "on-orbit" version - perhaps as a slip. That is interesting as well.

Sounds like a huge waste of mass compared to SEP tugs. Even a magnetic accelerator ring could offer the same benefit of reduced power consumption, but at a fraction of the mass and oscillation.

I'm not familiar with an accelerator ring. If that's a ring version of a linear accelerator, I'm not sure how one could say that's an improvement on a tether-based system. The tether has one motor that's in-use all the time and the mechanical tensile force is always held by the radius. A ring accelerator would have magnets that only engage when the payload is passing by and the entire ring circumference would have to be strong enough to withstand the radial force necessary through hoop stress which is very indirect.

[....]The engineer I was speaking to also mentioned an "on-orbit" version - perhaps as a slip. That is interesting as well.

Accelerator sitting in vacuum makes more sense than one in a dense atmosphere as ours. It's even more advantageous for bodies with lower gravity. Such as the Moon or Ceres.

The deltaV for LLO is ~1.7km/s (sans circularizing) and at 1000g (1/10 of their current design) you're looking at arm length of 295m.

Ceres is even better suited - it's escape velocity is 510m/s (equatorial) An arm with length of ~265 meters would achieve it with acceleration of 100g (1/10 of the Moon, 1/100 of Earth)

As for orbital based one I don't know. It does not seem feasible. It's not propellantless launch system when in orbit.

In theory, with the same 10'000g load and 3.5km/s (for Mars Insertion) the arm would have to be 125m long. One could sent lots of cube sats with this.

The kinetic E for 1 metric ton comes as ~1701kWh before losses. I'm assuming the energy for the structure is recoverable so, I'm not counting it here.

Starting from 1366 W/m2 (in LEO) and assuming 30% from Sun to drive, then a disk with diameter of 73 meters (4'151m2) would provide the energy required to accelerate 1ton within 1 hour. Assuming you got it working non-stop for 30 days during the launch window to Mars, then you could send as much as 720 metric tons. (per synode)

Then again, launching any mass in this way will result in orbit degradation that would require constant upkeep. Maybe with solar electric propulsion.

The engineer I was speaking to also mentioned an "on-orbit" version - perhaps as a slip. That is interesting as well.

Sounds like a huge waste of mass compared to SEP tugs. Even a magnetic accelerator ring could offer the same benefit of reduced power consumption, but at a fraction of the mass and oscillation.

I'm not familiar with an accelerator ring. If that's a ring version of a linear accelerator, I'm not sure how one could say that's an improvement on a tether-based system. The tether has one motor that's in-use all the time and the mechanical tensile force is always held by the radius. A ring accelerator would have magnets that only engage when the payload is passing by and the entire ring circumference would have to be strong enough to withstand the radial force necessary through hoop stress which is very indirect.

Maybe I'm confusing the various "catapult" launch systems. Isn't Spinlaunch doing the oscillating spiral? Their webpage seems to be nothing more than a background and an email link, and the rest of the internet isn't much more helpful on their designs.

The engineer I was speaking to also mentioned an "on-orbit" version - perhaps as a slip. That is interesting as well.

Sounds like a huge waste of mass compared to SEP tugs. Even a magnetic accelerator ring could offer the same benefit of reduced power consumption, but at a fraction of the mass and oscillation.

I'm not familiar with an accelerator ring. If that's a ring version of a linear accelerator, I'm not sure how one could say that's an improvement on a tether-based system. The tether has one motor that's in-use all the time and the mechanical tensile force is always held by the radius. A ring accelerator would have magnets that only engage when the payload is passing by and the entire ring circumference would have to be strong enough to withstand the radial force necessary through hoop stress which is very indirect.

Maybe I'm confusing the various "catapult" launch systems. Isn't Spinlaunch doing the oscillating spiral? Their webpage seems to be nothing more than a background and an email link, and the rest of the internet isn't much more helpful on their designs.

I don't know what an oscillating spiral is. As far as I can determine, there's a tether (really, an armature) that spins around a main hub in a vacuum until the tip is going 3 km/s. The payload (and the tip of the armature) are seeing 10,000 g's at launch and it takes about half an hour to get to speed. so you don't want anything but a purely tensile load-bearing structure I think.

Edit: Arm has a counterweight that will either be released into a dump or it's possible it might swing around half a circle and follow the main payload out the air locks.

The engineer I was speaking to also mentioned an "on-orbit" version - perhaps as a slip. That is interesting as well.

Sounds like a huge waste of mass compared to SEP tugs. Even a magnetic accelerator ring could offer the same benefit of reduced power consumption, but at a fraction of the mass and oscillation.

I'm not familiar with an accelerator ring. If that's a ring version of a linear accelerator, I'm not sure how one could say that's an improvement on a tether-based system. The tether has one motor that's in-use all the time and the mechanical tensile force is always held by the radius. A ring accelerator would have magnets that only engage when the payload is passing by and the entire ring circumference would have to be strong enough to withstand the radial force necessary through hoop stress which is very indirect.

Maybe I'm confusing the various "catapult" launch systems. Isn't Spinlaunch doing the oscillating spiral? Their webpage seems to be nothing more than a background and an email link, and the rest of the internet isn't much more helpful on their designs.

I don't know what an oscillating spiral is. As far as I can determine, there's a tether (really, an armature) that spins around a main hub in a vacuum until the tip is going 3 km/s. The payload (and the tip of the armature) are seeing 10,000 g's at launch and it takes about half an hour to get to speed. so you don't want anything but a purely tensile load-bearing structure I think.

Edit: Arm has a counterweight that will either be released into a dump or it's possible it might swing around half a circle and follow the main payload out the air locks.

The “slingatron” is a spiraling tube. The spiral is mounted on an offset motor, so it oscillates in a circle. The speed of this oscillation is matched to the travel of the payload such that It continuously falls outward, until it falls out the end of the tube.

The engineer I was speaking to also mentioned an "on-orbit" version - perhaps as a slip. That is interesting as well.

Sounds like a huge waste of mass compared to SEP tugs. Even a magnetic accelerator ring could offer the same benefit of reduced power consumption, but at a fraction of the mass and oscillation.

I'm not familiar with an accelerator ring. If that's a ring version of a linear accelerator, I'm not sure how one could say that's an improvement on a tether-based system. The tether has one motor that's in-use all the time and the mechanical tensile force is always held by the radius. A ring accelerator would have magnets that only engage when the payload is passing by and the entire ring circumference would have to be strong enough to withstand the radial force necessary through hoop stress which is very indirect.

Maybe I'm confusing the various "catapult" launch systems. Isn't Spinlaunch doing the oscillating spiral? Their webpage seems to be nothing more than a background and an email link, and the rest of the internet isn't much more helpful on their designs.

I don't know what an oscillating spiral is. As far as I can determine, there's a tether (really, an armature) that spins around a main hub in a vacuum until the tip is going 3 km/s. The payload (and the tip of the armature) are seeing 10,000 g's at launch and it takes about half an hour to get to speed. so you don't want anything but a purely tensile load-bearing structure I think.

Edit: Arm has a counterweight that will either be released into a dump or it's possible it might swing around half a circle and follow the main payload out the air locks.

The “slingatron” is a spiraling tube. The spiral is mounted on an offset motor, so it oscillates in a circle. The speed of this oscillation is matched to the travel of the payload such that It continuously falls outward, until it falls out the end of the tube.

Thanks for the information. I'd never heard about that before. I don't believe SpinLaunch is using that technology. I believe it's more of a traditional centrifuge. The particular problem the engineer I was speaking with works on wouldn't apply to a slingatron.

Back to SpinLaunch after the drama from SpaceX this weekend. I had a good conversation with an engineer there. Yes, there's a lot of velocity lost due to aero drag, etc. but that's been accounted for. If you take middle-of-the-road numbers for unknowns, they feel they can get 100 kg to orbit - though they're looking to scale even larger. Unlike other launch companies this engineer had worked for, no impossible mass fractions or record-breaking ISP numbers are involved. He hinted it's not just a single kick motor from launch but there might be two full stages (he wasn't clear). He suggested you just think of it like a "normal" launch where your pad velocity is 3 km/s. He felt there were no showstopper technologies left. Everything they need to do they've done, they've just got to scale it bigger. And so far all the scaling has followed the rules for what they expected. Yes, there's a lot of (reusable) infrastructure required to launch their first payload but much of the energy is being supplied by recoverable electricity. Obviously the g loading limits the types of payloads, but that's a market question and not a physics limitation.

Well 3 km/s into dense air still leaves a lot of delta V left to make up considering their drag loss will be huge. Two stage solid, large initial capital outlay for launcher, and limited range of g-load compatible payloads. Doesn't sound like a winning business model to me.

Launch Day = 80% 'Go'. Percentage does not include upper-level winds, which are poor.Backup Day = 80% 'Go'. Percentage does not include upper-level winds, which are poor (a little worse even than launch day).

Launch Day = 80% 'Go'. Percentage does not include upper-level winds, which are poor.Backup Day = 70% 'Go'. Percentage does not include upper-level winds, which are poor (a little better than the L-3 forecast; now the same as launch day).